In general, an wearing resistance composite is formed by dispersing ceramic powder having high hardness and high wearing resistance as a hardening phase in a matrix formed of metal. For use as such ceramic powder, various high-hardness powders, such as tungsten carbide (WC), titanium carbide (TiC), or titanium boride (TiB2), are used. However, these powders are costly, and they are difficult to be uniformly distributed in a metal matrix because of large difference in specific gravity with respect to the metal matrix when they are used to form a composite by using gravity casting or centrifugation casting. In addition, the binding force of these powders with respect to the metal matrix is not sufficiently enough due to their low adhesion.
In order to manufacture metallic parts or high-hardness metal-ceramic composite parts having high wearing resistance property or high corrosion resistance property using by casting or sintering, different powders may be combined each other to form a combined powder structure. To obtain excellent properties of the combined powder structure, powders are required to have an high binding force to bind each other. To obtain the high binding force, the contact area between the powders is partially melted, thereby the powders are combined each other. In the case of high-hardness ceramic composite materials, metal powder having a low melting point can be used as a binder to combine high-hardness ceramic powders.
Iron-boron binary compound may be used for a high-hardness ceramic powder used as a reinforcing agent or used to form a combined powder structure.
Iron-boron binary compound may be used as a reinforcing agent or as a high-hardness ceramic powder to form a combined powder structure. The iron-boron binary compound may be FeB or Fe2B according to the boron content. In detail, when the boron content is 8.83 weight %, the Fe2B compound having a melting point of 1389° C. may be formed, while when the boron content is 16.23 weight %, the FeB compound having a melting point that is higher than 1650° C. may be formed. In addition, when the boron content is 3.8 weight %, the iron-boron binary compound has the lower melting point of 1177° C. From among these, the Fe2B has a specific gravity of 7.3 g/cm3 and a hardness value of HK 1800 to 2000, and the FeB has a specific gravity of 7.0 g/cm3 and a hardness value of HK 1900 to 2100. In other words, the Fe2B and the FeB have both very high hardness property, excellent self fluxing property and adhesion property. Furthermore, since the specific gravity of an iron-boron compound is about 7.5 g/cm3, which is similar to that of iron-based metal, they are very suitable for manufacturing a metal composite including an iron-based metal matrix material by using gravitational casting or centrifugation casting.